PNNL

This study, a contribution to the EMF 25 scenarios on the role of energy efficiency in climate change mitigation, explores the value of technological improvement in the buildings, industry, and transportation sectors in meeting 2050 CO2 emissions mitigation targets in the United States. Six scenarios of future end-use technology evolution are analyzed without any future emissions mitigation policy, and with two linear emissions constraints that begin in 2012 and achieve 50% and 80% reductions from 1990 CO2 emissions levels in 2050.The scenarios show that end-use technologies are important for reducing near-term energy demand and CO2 emissions, and advanced transportation technologies in particular are important for allowing the energy system as a whole to achieve deep emissions reductions in a cost-effective manner. Total discounted economic costs of meeting the emissions constraints are reduced by up to 53% by advanced end-use technologies, and similar cost reductions are observed when the policies allow inter-temporal shifting in the emissions pathways (i.e., banking and borrowing). The scenarios highlight the importance of end-use technologies that facilitate electrification and decrease the direct use of hydrocarbon fuels through efficiency improvement, but we stress that end-use technology advancement should be complementary to technology advancement in energy supply.